Armature



Patented Mar. 11, 1890.

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(No Model.)

N. PETERS. mommy-pur. wunngwn. u. c.

WIT/VESSES UNITED STATES lPATENT OFFICE.

ROBERT L. COHEN, OF OAMDEN, NEW JERSEY.

ARMATURE.'

SPECIFICATION forming part of Letters Patent No. 423,026, dated March11, 1890.

Application filed June 19, 1889. Serial No. 314,793. (No model.)

To @ZZ whom it may concern:

Be it known that I, ROBERT L. COHEN, a citizen of the United States,residing in Camden, in the county of Camden and State of New Jersey,have invented certain new and useful Improvements in Armatures, of whichthe following is a specification.

This invention is designed as an improvement on the invention describedlin Letters Patent No. 397,340, granted to me February 5, 1889.

The object of this invention Lis to provide more efficient means forventilation of the yarmature thanis described in said Letters Patent,and to accomplish such object by less expensive apparatus.

The invention described in said Letters Patent consisted in building upan armature of a series of bobbins. Each bobbin was composed of two enddisks with an interposed tubular or cylindrical shell forming the coreof the bobbin upon which iron wire or wrought iron rings were placed,constituting the magnetic element of the armature. Any desired number ofthese bobbins was slipped over a hollow shaft and a spacing diskordevice was inserted between each two bobbins in order to provide foran efficient cooling of the armature. The ventilation was secured byperforating the hollow shaft, so that air from the same might pass into'the space within the bobbins and through lateral perforations into thespaces between the bobbins. This construction formed what might betermed a honeycombed or cellular structure through every part of whichthe air might permeate, thus preventing all liability of heating. Thisconstruction I have found to be more expensive than is desirable, inthat the hollow shaft must be carefully manufactured, and also formed ofmore expensive material. My present design is therefore to maintain theVentilating properties of the armature, and at the same time utilize aconstruction which isv less expensive of fabrication.

cut away next to the sleeve, so as to leave a free space throughout thelength of the sleeve for the passage of air. The air enters the spacethrough the ends of the armature and communicates with the interior ofthe spools and the spaces between the same.

The construction in detail will now be described with reference to theaccompanying drawings, in which- Figure l represents a longitudinalsection of the armature constructed in accordance with my invention.Fig. 2 is a transverse sectionof the same on line X X of Fig. l, andFig. 3 is a perspective view of one of the spacing plates or disks ofthe armature.

Arepresents the main shaft of the armature, which in this instance issolid. Upon the shaft is placed a brass or other non-magnetic sleeve B.This sleeve has formed upon it a number-say three-of longitudinalrectangular ribs 1J, which project some distance from the surface of thesleeve. The end disks c c are provided with a central opening ofslightly greater diameter than the greatest diameter of the sleeve, sothat when the said end plates are slipped upon the sleeve a space c willbe left between the sleeve and v the edges of the opening in the disks.These openings in the disks are also notched at intervals to fit overthe longitudinal ribs l). This construction prevents any movement of theplates with respect to each other and insures a rigid structure. Theshellsare placed between the disks in annular grooves therein in themanner described in the abovementioned Letters Patent. Between each twospools is placed a brass spacing-diskv D, having three or morerwings orlugs dformed upon one side integrally therewith. The

central perforation of these brass disks is of similar construction tothe perforations in the end plates of the spools, so that a free spacewill be left for passage of air between the disk and the sleeve. Thenuts or collars binding the spools and disks together are threaded overthe ends of the sleeve up against the end spools of the armature.Ordinarily these nuts would cut off the supply of air to the air-spacearoundthe sleeve, and in order to obviate this diiculty I bore a seriesof holes through the nuts or collars,

which will communicate with the said space around the sleeve. The headsof the armature are formed by skeleton plates e e, which admit air tothe armature from the outside.

It will thus be seen that I have secured the Ventilating properties ofthe armature described in the aforesaid Letters Patent, in that all ofthe chambers within the armature communicate with one another and withthe common air-passage around the sleeve. I have thus done away with theexpensive hollow perforated shaft and with the necessity of perforatingthe end plates and brass spac ing-disks.

Having thus described my invention, I claiml. In a dynamo-electricmachine or motor, the combination, with a solid shaft, of a sleeve ofnon-magnetic material thereon, said sleeve being provided externallywith longitudinal ribs and a series of hollow spools mounted upon thesleeve, said spools each being' built up of a pair of end plates and aninterposed cylindric shell, the end plates having a central perforationthrough which the shaft passes, said perforation being of a greaterdiameter than the external diameter of the sleeve, as set forth.

2. In a dynamo-electric machine or motor, the combination, with a solidshaft, of a sleeve of non-magnetic material thereon, said sleeve beingprovided externally with longitudinal ribs and a series of hollow spoolsmounted upon the sleeve, said spools each being built up of a pair ofend plates and an interposed cylindrical shell, the end plates having acentral perforation through which the shaft passes, said perforationbeing of a greater diameter than the external diameter of the sleeve andprovided with notches in which the longitudinal ribs extend, for thepurpose described.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

ROBERT L. COHEN.

lVitnesses:

A. P. RUTHEnFoRD, J. CLAYTON Ene.

